Grinding-mill.



D. COLE.

GHIND|NG MILL. APELICATION FILED rAPR. 28, l9l3.

Patented Apr. 10, 191'?.

2 SHEETS--SHEET l.

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D, COLE.

GRINDJNG MILL. ABPL'lc/moufmu APR. 2s, 191s.

Patented. Apr. 10,1917.

2 SHEETS-SHEET Z.

20 returned to the ing chambers.

bei? a settling action takes place. The finest particles are carried out through the discharge trunion, while the coarser settle be- .tween ribs 13 in the sorting chamber and are then conveyed back 'to the grinding chamber. Ehe radial ribs 11 by lifting and then discharging solid material down .f through the outflowing water, assist the sortaction. I 'I lo he use of a sorting chamber of smaller diameter than the'grmding cham'ber'is of special advantage in thatthere is no ltendency for the unground charge in the mill to Stilow into they-sorting chamber. The only 15 .solid material which enters the sorting chamber is that which has been ground fine enough to be sustained by-'the .outflowin water current. The coarse portions of t is are precipitated inthe sorting .chamber and thence grinding chamber, but Athe finely ground portions Water and overfiow with it through the discharge opening.

e operation of my 4millsecures a marked economy of power particularly in cases where fine grinding is necessary, For example a plain cylindrical mill for doing such grinding -wil commonly be twenty-two feet in length, -Tests have shownthat about 50% so 'f the reduction occurs in the first five feet and'about 70% in the frst'ten feet, twelve i r feet "being necessa'r to'efect the final 30%'- of the reduction', t e 'grinding action being less, due to the smallness of the particles. Th

is practically directly proportional to the length of the mill, so that obviously the efiiciencyof the mill'can be greatly increased if the desired. grinding can be effected in a' 40 shorter miillin `vfvhichf the fine grinding takes pllace in the presence ofthe coarser parti- I effect.' this pur ose'by adding-tofs, relatively short grinl 'ing c V amber, a sortlng 45. chamber of suitable-length, tl1rouglr"`which `water flows to discharge and in which is ,ef-y fected a sorting action basedgon the laws o f bodies l'settling -.in water. By this sorting action the particlesv which are sufficiently' fine to remain 1n suspension through the lengthof the sorting chamber are discharged while.

those which are precipitated are returned to the grinding chiurlberT Within certain lim'- its the fineness of rinding can be varied by fgwatr to the mill .ilnd by vt v 'ithe llen h' of t e grinding an sort ry ng he roduct of the mill is characterized by' un'i ormity of size;

'Variousiforms of sorting chamber will suggest themselves and also variousl forms of -return-conveying-devices for the prec'lpl# tated material,- but I prefer those shown as the most s'im le.' For example it ls-'n ot necthat -t e iralrib 13 be continuous,

,11 5 "orfthat it extend-t length of the chamare sustained by the e power consumed by a cylindrical mill` therewith, said sorting chamber having a freeI axial overflow opening above`the bottom of 'said chamber and at a point remote 80 from the grinding chamber for producing. an outflowin r water current through the sorting cham )er to carry ground material from the grinding chamber; and backwardly feed mg conveying means in the sorting chamber for conveying back to the grinding chamber material precipitated from said outfio-wing water current,

2. In a grinding mill the combination of a. rotatable grinding chamber; means -for 90 feeding water and material to be ground to the .grinding chamber, a water conveying sorting chamber turni-ng with 'the grinding chamber and in free axial communication therewith, Said sorting :chamber 'having Va 95 free axial overflow opening above-the bottom of said chamber and at a point remote from the grinding chamber for producing an out' flowing Water current through the @sorting chamber to carry ground material from the grinding chamber; and a backwardly feeding helical conveying rib on the Wailsof said sorting chamber for conveying back to the grinding chamber material precipitated from said outfiowing water current. Y

3. In a grinding :mill the' combinationof a vmember rotatable on a substantially-horizontal axis and providedjwi'th "agriding chamber and a' communicating .watericonveying sorting chamber of less diameter ar-- ranged in axial .alineme'nh andV furtherfprof vided with an axial overflow discharge' open= ing leading from said: sorting chamberrat a point remote from the grinding chamber and above the bottom of the'sorting chamber; andmeans for feeding to saidgrinding b A' lalinernent.;mean's fofeedingvvater teria-'ll to be ground tosaid lgrinding cham ber; and l backwardly fee .conveyn means mounted .in said sorting chamber' a Q '13o .er .d-... ing chamber, asortin .chamber of less" 'd i 12o Azo \ with and adapted to effectfment; means for feeding to be ground to said grinding chamber; and4 `in the sorting chamber upon material precipitate operable oy the rotation of said rotatable bein in free communication with each other and in 'substantially horizontal axial alinewatery and material a backwardly feedin helical conveyer member fixedly mounte in said sorting chamber to turn therewith, for conveying back to said grinding, chamber solid material precipitated from said water in its flow through the sorting chamber to said discharge opening. i

6. In a grinding mill the combination of a rotatable` spheroidal grinding chamber;

a cylindrical sorting chamber of less diameter,'xnountedto rotate coaxially therea sorting action by free settling in water; an inclined inwardly projecting conveyor blade 4mounted chamber andfadated to `exert a feeding tendency toward t e rindng in the sorting chamber, the sorting chamber being inter osed. between the grinding chamber and t e discharge from the mill;` and means for feeding to the grinnm chamber, water and material to be groun 7. In a grinding :nill the combination of a rotatable spheroi ial grinding chamber; a cylindrical sortir g chamber of less diameter, mounted to rotate ooaxially therewith and adapted t) effect a sorting action by f ree settling in water; a spiral inwardly proJecting blade mounted in the' sorting chamber and adap'ved to exert` a feeding tendency toward the grinding chamber, upon material precipitated in the sorting chamber, the sorting chamber being interposed between the grinding chamber and the discharge from the mill; a Iplurality of radial venes mounwed in the sorting `chamber 'adjacent the pointof discharge fromv the mill; and means ,for feeding to the grinding chamber, water and material to be 5I ground.

8. A rind'ing cl. amber for mills comprising a g obular shell formed in sections, and a lining therefor comprising a plurality of curved segmental lining bars provided with. marginal inwardly extending ribs, said bars being adapted to sustain themselves in osition within said shell,4 by their arche arrangement. l

In testimony whereof I have "signed my 65 name to this speci cation in the presence of two subscribing witnesses. 1 n DAVID COLE.

Witnesses:

L. T. PAH E, W. J. Lamine. 

